NDP candidate Linda McQuaig was on a political panel when she cooly claimed that "a lot of the oilsands oil may have to stay in the ground if we're going to meet our climate change targets."

Her words triggered a firestorm.

Evidence that an NDP government would "wreck the economy," according to Conservative leader Stephen Harper; proof of "extreme positions," according to Liberal leader Justin Trudeau.

The NDP was quick to clarify that its official stance calls for no limits on oil sands extraction. But after all the partisan political shots had been fired, one big question remained unanswered — and that's whether Canada can in fact continue to extract more oilsands oil "from the ground" and still meet its carbon reduction targets.

The targets are real: Canada has signed on to ambitious international goals and pledged to get the econonomy off carbon by the end of the century. But oilsands production keeps expanding, and that production is the fastest-growing source of greenhouse gas emissions in Canada.

To help us take on this important question, we were joined by two guests:

Keith Stewart thinks McQuaig did us a favour with her comments because she said out loud the environmental truth no one seems permitted to speak. He's a climate and energy campaign coordinator for Greenpeace Canada, and he joined us in our Toronto studio.

But Dave Sawyer says that statement might not be exactly correct because there are ways to lower the carbon emissions coming from oilsands production. Sawyer is an economics advisor and the CEO of EnviroEconomics, a consultancy in Ottawa. He joined us from PEI.